The present invention relates to wire forming machines in general, and more particularly to improvements in machines for converting a strand of wire into a product of undulate or meandering shape. Still more particularly, the invention relates to improvements in machines which can impart to a continuous strand of wire a configuration which enables the deformed strand to be readily converted into discrete binders of note books, calendars or analogous stationery products. Reference may be had to U.S. Pat. No. 4,020,516 granted May 3, 1977 to Gomez. FIG. 1 of the patent shows a continuous strand of undulate wire, and FIG. 2 shows the binder which is obtained by imparting to the prongs of the undulate wire a circular shape.
Certain presently known wire forming machines employ two wheels which rotate about mutually inclined axes and carry pins which move away from each other during one half and toward each other during the other half of each revolution of the wheels. A rotary looping arm alternately winds the wire around successive pins of the two wheels while the pins move away from each other. The looped wire is tensioned so that each of its sections assumes a predetermined shape during travel toward the location of maximum distance between the pins. The stress upon the loops is thereupon relaxed so that the undulate product can be readily lifted off the pins and transported to storage or directly to a further processing machine.
A drawback of such deforming machines (disclosed, for example, in U.S. Pat. No. 3,691,808 granted Sept. 19, 1972 to Calvert et al.) is that the mounting of wheels for rotation about mutually inclined axes presents serious problems. Furthermore, the rotary looping arm must perform a complex movement in order to bypass the pins which approach the looping station as well as those pins which advance beyond the looping station. Still further, the patented machine is rather bulky and certain parts thereof are not readily accessible for inspection and/or replacement. In addition, the conversion from making undulated wire with prongs of a first length to the making of undulate wire with longer or shorter prongs is a time-consuming operation which takes several hours.